SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1a38f57f182bd8cb2befef09d263de0e610a71ac8823212990c13ddffd92427f' 
  AND token = 'g43L/DCuVZoQpni2ax282PSmYdKUwmcRPcwz2vU0GEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}